How much do you know about the world? Hans Rosling, with his famous charts of global population, health and income data (and an extra-extra-long pointer), demonstrates that you have a high statistical chance of being quite wrong about what you think you know. Play along with his audience quiz — then, from Hans’ son Ola, learn four ways to quickly get less ignorant.

Hans Rosling
Global health expert; data visionary
In Hans Rosling’s hands, data sings. Global trends in health and economics come to vivid life. And the big picture of global development—with some surprisingly good news—snaps into sharp focus. Full bio

Ola Rosling
Director of the Gapminder Foundation
Ola Rosling is the director and co-founder of the Gapminder Foundation. Previously, he was the Google Public Data product manager. Full bio